diff --git a/CHANGELOG.md b/CHANGELOG.md
index 21544fa..17a3f9b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,16 @@ of current runtime behavior, see [`docs/CURRENT-STATE.md`](docs/CURRENT-STATE.md
## [Unreleased]
+### Changed
+
+- The Material Symbols icon font is now requested as a subset of the glyphs the
+ app actually renders, and the unused Material Icons Round stylesheet is gone.
+ Loading the app pulled 442 kB from Google Fonts over six requests, 330 kB of
+ it the complete icon font served for the 28 glyphs on screen; it now pulls
+ 115 kB over five. `src/materialSymbolsSubset.test.mjs` fails when a source
+ names a glyph the subset is missing, because an absent glyph renders as its
+ own name rather than as a missing-glyph box.
+
### Fixed
- Mapped-site outages show their scheduled retry countdown and distinguish
diff --git a/index.html b/index.html
index e8b0b8d..50a7951 100644
--- a/index.html
+++ b/index.html
@@ -9,8 +9,11 @@
-
-
+
+
diff --git a/src/materialSymbolsSubset.test.mjs b/src/materialSymbolsSubset.test.mjs
new file mode 100644
index 0000000..3349e74
--- /dev/null
+++ b/src/materialSymbolsSubset.test.mjs
@@ -0,0 +1,88 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { readFileSync, readdirSync } from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const SRC_ROOT = fileURLToPath(new URL('.', import.meta.url));
+const REPO_ROOT = path.resolve(SRC_ROOT, '..');
+const INDEX_HTML = path.join(REPO_ROOT, 'index.html');
+
+/** The glyph written as element text: `radar`. */
+const SPAN_TEXT = /class="[^"]*material-symbols-outlined[^"]*"[^>]*>\s*([a-z0-9_]+)\s*} glyph -> the first file that names it.
+ */
+function referencedGlyphs() {
+ const found = new Map();
+ for (const file of sourceFiles()) {
+ const source = readFileSync(file, 'utf8');
+ const relative = path.relative(REPO_ROOT, file).split(path.sep).join('/');
+ const add = (glyph) => { if (!found.has(glyph)) found.set(glyph, relative); };
+ for (const match of source.matchAll(SPAN_TEXT)) add(match[1]);
+ for (const match of source.matchAll(TEXT_ASSIGNMENT)) {
+ const statement = match[1].replaceAll('?.', '.');
+ const assigned = statement.includes('?') ? statement.slice(statement.indexOf('?') + 1) : statement;
+ for (const literal of assigned.matchAll(STRING_LITERAL)) add(literal[1]);
+ }
+ }
+ return found;
+}
+
+/** The `icon_names` list index.html asks Google for. */
+function subsettedGlyphs(html = readFileSync(INDEX_HTML, 'utf8')) {
+ const match = /Material\+Symbols\+Outlined[^"]*[?&]icon_names=([a-z0-9_,]+)/.exec(html);
+ assert.ok(match, 'index.html must request Material Symbols with an icon_names subset');
+ return new Set(match[1].split(','));
+}
+
+test('every glyph the sources render is in the icon_names subset', () => {
+ const subset = subsettedGlyphs();
+ const missing = [...referencedGlyphs()]
+ .filter(([glyph]) => !subset.has(glyph))
+ .map(([glyph, file]) => `${glyph} (${file})`);
+
+ assert.deepEqual(
+ missing,
+ [],
+ 'Glyphs named by the sources but absent from the index.html icon_names list. '
+ + 'Add them there — an unlisted glyph renders as its own name on screen: '
+ + missing.join(', '),
+ );
+});
+
+test('the unused Material Icons Round family is not loaded', () => {
+ // A second icon font, 173 kB, for a family no source ever uses — and
+ // src/cockpitMarkup.test.mjs already asserts the markup must not use it.
+ const html = readFileSync(INDEX_HTML, 'utf8');
+ assert.doesNotMatch(html, /Material\+Icons\+Round/, 'index.html loads an icon font nothing renders');
+});